Fix incorrect parenthesis

Also add parenthesis in places to make things mofre clear.

Author: mattico

src/float/add.rs

@@ -43,7 +43,7 @@ macro_rules! add {
 
                 if a_abs == inf_rep {
                     // +/-infinity + -/+infinity = qNaN
-                    if a.repr() ^ b.repr() == sign_bit.0 {
+                    if (a.repr() ^ b.repr()) == sign_bit.0 {
                         return (<$ty as Float>::from_repr(qnan_rep.0));
                     } else {
                         // +/-infinity + anything remaining = +/- infinity
@@ -100,7 +100,7 @@ macro_rules! add {
             // The sign of the result is the sign of the larger operand, a.  If they
             // have opposite signs, we are performing a subtraction; otherwise addition.
             let result_sign = a_rep & sign_bit;
-            let subtraction = (a_rep ^ b_rep) & sign_bit != zero;
+            let subtraction = ((a_rep ^ b_rep) & sign_bit) != zero;
 
             // Shift the significands to give us round, guard and sticky, and or in the
             // implicit significand bit.  (If we fell through from the denormal path it
@@ -115,7 +115,7 @@ macro_rules! add {
             if align.0 != 0 {
                 if align < bits {
                     let sticky = ((b_significand << (bits - align).0 as usize).0 != 0) as <$ty as Float>::Int;
-                    b_significand = b_significand >> (align.0 | sticky) as usize;
+                    b_significand = (b_significand >> align.0 as usize) | Wrapping(sticky);
                 } else {
                     b_significand = one; // sticky; b is known to be non-zero.
                 }
@@ -173,8 +173,8 @@ macro_rules! add {
 
             // Final rounding.  The result may overflow to infinity, but that is the
             // correct result in that case.
-            if round_guard_sticky > Wrapping(0x4) { result += one; }
-            if round_guard_sticky == Wrapping(0x4) { result += result & one; }
+            if round_guard_sticky.0 > 0x4 { result += one; }
+            if round_guard_sticky.0 == 0x4 { result += result & one; }
             return (<$ty>::from_repr(result.0));
         }
     }